In recent years, in order to improve traffic flow and reduce air resistance to improve fuel efficiency, a technique has attracted attention which makes a plurality of vehicles travel in a row at a short inter-vehicle distance. As the technique for making the vehicles travel in a row (which is also referred to as a “vehicle group traveling technique”), a system disclosed in Japanese Unexamined Patent Application Publication No. 10-162282 has been proposed. In the system, each of the vehicles behind the first vehicle in a vehicle group controls the distance from the first vehicle to achieve vehicle group traveling using a plurality of vehicles. In this method, each of the vehicles behind the first vehicle rapidly responds to a disturbance applied to the first vehicle in the vehicle group. Therefore, an error in the inter-vehicle distance is not propagated and the row of the vehicles is not disarrayed.
Patent Literature 1: Japanese Unexamined Patent Application Publication No. 10-162282